Combination comprising a hot-gas engine and a piston machine driven thereby



June 26, 1951 A. A. DROS 2,558,481

COMBINATION COMPRISING A HOT-GAS ENGINE AND A PISTON MACHINE DRIVEN THEREBY Filed July 19, 1948 3 Sheets-Sheet 1 INVEN TOR. ALBERT A .3205

AGENZT June 26, 1951 DRQS 2,558,481

COMBINATION COMPRISING A HOT-GAS ENGINE AND A PISTON MACHINE DRIVEN THEREBY Filed July 19, 1948 3 Sheets-Sheet 2 INVENTOR. AZIBHQTA. DEG/5' AGEJVZT June 26, 1951 A. A. DROS COMBINATION COMPRISING A HOT-GAS ENGINE AND A PISTON MACHINE DRIVEN THEREBY 3 Sheets-Sheet 5 Filed July 19, 1948 AGFNI.

Patented June 26, 1951 COMBINATION COMPRISING AHOT-GAS EN- AND A PISTON MACHINE DRIVEN THEREBY Albert A. Dros, Eindhoven, Netherlands, assignbr to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Applicati y 1 nseen 3.9.5.44

In the Netherlands August 23, 1947 8 Claims. 1

This invention relates to a combination comprising a hot-gas piston apparatus and a piston machine which is either driven thereby or which drives the combination. The term hot-gas piston apparatus is to be understood to mean a hot-gas engine-or a refrigerating machine operating on the reversed hot-gas engine principle.

The invention enables the hot-gas piston apparatus and the piston machine driven thereby or driving the combination to be combined so as to obtain a combination extremely compact, light in weight andsimple in construction. Furthermore, such a combination may be so constructed that the mass forces and moments of the moving parts substantially neutralise one another.

In addition, the mechanical efficiency of a combination constructed in accordance with the invention is higher than thatoi the combinations hitherto known.

Finally, the gas pressures permissible in a combination according to the invention are higher than those usedin the combinations hitherto known, which again favourably affects the chiciency and the dimensions and weight of the combinations.

The combinations constructed in accordance with the invention have thecharacteristic that the stroke of the pistons and the phase difierence between the pistons of the hot-gas piston apparatus are maintained constant by a driving mechanism which is cohstituted-solely'by reciprocating parts. Such driving mechanisms applied to combustion motors or steam engines are already known. Thus, since combustion motors orsteam engines, however, comprise various-valves or slides which are required to be actuated at the right moments and since the movementsthereof may be derived from a rotary shaft more readily than from reciprocating members, driving mechanisms comprised solely of reciprocating members and in which, therefore, no rotary shaft'is provided, are not particularly suitable for use in combinations in which the driving engine is a'combustion motor or asteam engine.

This disadvantage does not apply to combinations according tothe inventiomsince neither hot-gas engines nor most of the piston machines driven such, for example, as compressors or pumps, comprise valvescr'slideswhichare required to be actuated mechanically. .Oii the contrary, not-gas engines and also refrigerating machines operating .on thj reversed he gas engine principle onl y .i'iiuir piston move ,nts with a suitable phase diff ence between twb pis j tcns acting upon one ,sp Sincfeth'e drivin g'mechanism u; diiicomb a.- t'io'n's according to the invention are, for .matic reasons, always required to be s truc'ted that a phBJSIe'-.difi""hce Of .9 5 the movements of two pistons is htaihed, such driving mechanisms are ,XdcIlentl y suit able for synchronising the piston movements of the last-mentioned apparatus.

in one advantageousemboi imjent of ,thejir'ive'ntion, theycombination'has the e'harac the phase dififerenc'erequired'between e ments of two pistons of the hot-gas engine .belonging to a single cycle is obtained by coupling the"movements of :thepistonsbY means of one or more members reciprocating at right angles to the-movements of the pistons with double the frequency of the reciprocating movements efthe' pistons. Inthis case, a simple construction may be obtained if the pistons of the'hot-gas apparatus and the piston or pistons of the machine driven'ar coupledfbymeans of cranks. Further more, it may be advantageous if the working pistons of the hot-gas apparatus move in a sense opposite to that of the pistons of the driven or driving machine.

In a further advantageousembodiment of the invention, the combination has the characteristic thatthestrai'ght-guide of the piston rods is pro vided by means of straighbguided members moving with double "the frequency at right angles to the piston "rods, and levers by which the said members are articulated to the --piston rods, the centre of each -lever being constrained-to describe a pathin the form of an arc of a circle by means or cranks engaging this centre.

in this case a simple construction may Jacob tainedif thecombinajtion comprises a i-cylinder hot-gas engine and amachine to be driven which also comprises four cylinders. In such a construction, the four *piston rods, each of which connects onepiston of the engineto one piston of the machine to 'be driven, intersect a plane normal to the piston rods at the corners ojf,ja square, rectangle or parallelogram. Inthis com bination a determined phase difference is maintained between two piston rods belonging to one pair, the four piston rods being divided into two pairs, by means of a member reciprocating with double the frequency at right angles to the piston rods and articulated to the associated piston rods, while each pair of piston rods, which move with double the phase difierence of the first-mentioned phase difference, are interconnected by means of a coupling member.

For a simple arrangement, it may be of importance that the driving mechanism is provided between the cylinders of the hot-gas engine and the cylinders of the machine driven.

The invention affords particular advantages if the piston rods of the hot-gas engine are immovably connected to corresponding piston rods of a refrigerating machine, operating on the reversed hot-gas engine principle, which is to be driven by this hot-gas engine. The invention will now be explained more fully V by reference to the accompanying drawing wherein:

Figure 1 is a vertical cross-sectional view of a diagrammatic representation of one form of the invention wherein a hot-gas engine drives a piston machine which is a refrigerating machine via common piston rods;

Figure 2 is a view similar to that shown in Figure 1 but of a modification of that structure wherein piston machines are linked into the combination so that the pistons of the last machine move in a sense opposite to those of the hot-gas engine;

Figure 3a is a vertical cross-sectional view of a diagrammatic representation'of another form of the invention wherein fourcylinders are incorporated in the combination; the section being taken on the line HI 111 in Figure 4';

Figure 3b is another vertical cross-sectional view of the embodiment shown in Figures 3a. and 4; the section being taken on the line III'-IIl in Figure 4; v

Figure 4 is a diagrammatic representation of a horizontal sectional view of the driving mechanism illustrated in Figures 3a, and 3b; and V 4 V Figure 5 is a plan view of the combination shown in Figures 3a and 3b taken in the direction ofthe arrow H in Figure 3b, for example. 7

' Thearrangement of the combination shown in Fig. l is as follows: The piston in cylinder 2 of the hot-gas engine is immovably connected, by means of hollow piston rods 3, to the piston 4 in cylinder 5 of the machine driven, which in this case is a refrigerating machine operating on the reversed hot-gas engine principle.

Similarly, the piston 6 in cylinder 2 is immovably connected, by means of the piston rods 8, to the piston 9 in cylinder 5. The two pistons 6 and 9 operate as displacers in the working spaces of the hot-gas engine and the refrigerating machine, respectively. The working space of the hot-gas engine comprises a hot portion HI, and a cold portion Interposed therebetween are a heater l2, a regenerator |3,and cooler I4. Similarly, the working space of the refrigerating machine comprises a cold space l5 and a hot space I6, between which are interposed a cooler H, a regenerator l8 and a heat-absorber I9.

The piston rod 3 is articulated by means of levers 20 and 2| and bearings 22, 23 and 24, 25, respectively, to reciprocating members 26 and 21 respectively, which are arranged symmetrically in order to avoid any action of transverse forces upon the piston rods 3.

The two reciprocating members 26 and 21 are in this case comprised of two balanced levers which are centrally pivoted at 28 and 29, respectively.

The movement of the bearings 23 and 25 of the balanced levers is substantially at right angles to the piston rods 3.

It will readily be evident that the frequency of the number of deflections of the balanced levers 26 and 21 is twice that of the reciprocating movement of the piston rods 3. v

Similarly, the piston rods 8 are articulated by means of levers 30 and 3|, respectively, and bearings 32, 33 and 34, 35, respectively, to the other side of the balanced levers 26 and 21, respectively. When the piston rods 8 pass through the centre of the stroke, the levers 30 and 3| are at right angles thereto, thus limiting the deflection of the balanced levers 26 and 21 to one direction. Thus, the stroke of the piston rods 3 is also limited in either direction.

Similarly, the stroke of the piston rods 8 is limited in either direction, since at the. centre of the stroke of piston rods 3 the deflection of the balanced levers 26 and 21 in the other direction is limited by the levers 2|] and 2|;

In this manner the two piston rods 3 and 3 mutually limit their strokes, thus alsomaintaining a phase difierence of between the movements of the two piston rods. In order to balance the mass forces produced by the moving parts, the levers 20, 2| and 30, 3| are provided with counterweights 36, 31, 38 and 39, respectively. The combination shown in Fig. 2 essentially differs from that in Fig. 1 only in that, instead of oounterweights provided on the levers 20 'and 2|, two pistons 40 and 4| of the machine driven are operated by the leve'rs 20 and 2| in a senseopposite to the movement of pistons of the hotgas engine.

The machine driven is in this case a compressor comprising cylinders 42 and 43, which compressor is of the double-acting type.

The cylinder 5, together with the two pistons 4 and 9, constitutes in this case a second cylinder of an engine, so that the combination now comprises two engines. The operation of this combination will be readily evident after the foregoing. 7 e

In some cases such a combination will afford advantages with respect to a combination as shown in Fig. 1 since, on account of the movement of the pistons in opposite senses, some counterweights may be dispensed with and the combination may be equipped in a simple manner with two engines. 7 V In the'combination shown in Figures 311,317, 4 and 5 use is made of a driving mechanism which incorporates some fundamental improvements.

The driving mechanisms used in thecombinations shown in Figs. 1 and 2 are of the double-- that' a double-acting con-1 This is ensured by. providing; exactly straight:

spectively, the centre? of. which is' located inzthe centre line. of the" piston rods 1, 2,. 3:, 4,. respec--: tively, and the ra'diusof which ishalf the; length. of. the lever. An exactlystraight guideisuthus' also providedfor the pistonmods, so that went-- a ter are not subject to lateial reaction forces;

With the adoption of such an arrangementxtherel are no longer objections. against the use: 01's."

driving. mechanism: of the single acting typeu A second. difference between this. combination? and the.combinationsshownintFigs 1 and "2iconsists in that the former combination is. const-i tuted by 4. parallel oylinders 1 3, 23, 331and143 of the hot-gas engine'aandA parallel cylinders I4; 24, 34. and 44, arranged coa'xially therewith, of. the machine driven. a The cylinders are so' positioned that the piston rods-l, 2, 3 and 4,. by which the pistons i5, 25, 3.5 and 45 in the hot-gasengine cylinders 13, 23, 3.3 and 43, respectively, are connected to the pistons I6, 26, 36 and 46, respectively, in thecylinders 14,124, 34 and 44 respectively ofthe machine driven; intersect a plane" at' rightanglesi to the piston rods at the'corners of a square. If desired, the-cylinders may alternatively be'so positioned that this isa rectangle or'a' parallelogram. Such an arrangement" per" se of the cylinders of a hot-gas engine is already known;

The movementsofthe pistons I5, 25, 35, and 4'5, as controlled by the cra-nk arrangement described, is such that piston leads by 90 with respect to piston 25, piston leads by 90 with respec'tto piston'35, piston leads by 90 with respect to piston, and piston leads by 90 with respect to piston 1"5". In a manner already known the bottom of each 'pistonvl 5 ,..2l5, 35 and 45 may act upon a cold space (thexcbottom ofeach cylinder, for. example 13) which communicates via a cooler 63, a regenerator 62, and a heater 6|, witlrjthe hottop of acylin der, for example 23', so that the bottom of -one' piston and the 'top of a subsequent-piston jointlyact' upon the same space as clearly shown in Figures 3a and 3b.

If the machine driven is airefrigeratingmachine operating onthe reversed hot-gas engine principle, this may be constructed in a similar manner.

The operation of the driving mechanism described above is the following. When piston rod l is at the centre of the stroke, the lever H is at right angles thereto, thus limiting the deflection (reciprocation in this case) of the member to the right only. The stroke of the piston rod 2, which is also connected to this member by means of the lever 2|, is thus limited in either direction in a manner similar to that described with regard to the driving mechanisms shown in Figs. 1 and 2. When piston rod 2 is at the centre of the stroke, the deflection (reciprocation) of the member 50 is thus limited to the left only, the stroke of the piston rod I thus being limited in either direction. Consequently, the piston rods I and 2 reciprocate with a phase difference of 90 and mutually limit their strokes.

.Exactly' the; same operation takes place be tween; the: piston rod's 3xand 4; The requirement that the movements of the piston rods 2 3 and- 4,. 1 respectively: should? also take place with- 9.190"

phase diiference may also be formulated differ entl'y;.viz; that. the piston rods 3 and 4, I" re spectively are required to move-rwith a phase diT-'= ference of This is ensured in the following; way. a

i .Thecrank: l 2, which engages at the" centre of lever M l and which is pivoted on the frame" at. I'J' islimmovably connected to the cra-nk I 9 The crank 32,. which:- engages at the centre of lever 31 and; which is' pivoted on: the frame at '37,: is

immovably. connected to the-crank 39.

Since the twocranks I 9 and 39 ar'e'connected by meansof a coupling rod 53, the cranks l2 and 32' are required to move ir i-s'ynchronism. It" is;

readily clear that the pistonrods I and 3. are thus constrained to move inopposite senses and hence: with: a phase difier'ence o'f 180.

Similarly, the cranks 22 and: 42 are synchro nized-byLm'ea'ns of a-coupling 1 06154; by which the two cranksZB and 49;-which' are integral with-the cranks 22 and 42, are: interconnected" and by which the piston rods 2- and 4 are constrained to move in opposite senses and hence witha phase difference at 180.

I'itorder to balance the 'combination the cranks I2,. 22,. 32 and 42 are provided with counten weightscranks are extended beyond the fixed bearings I1, 21:, 31- and 41 respe'ctiv'elyand carry other co-untcrweightsbearing the numbers I 8, 28'; 3E

and 48, respectively.-

The combinationmay be substantially ba lanced by means of the said counter-weights which move in a sense opposite tethat of th'e-pistons.-

As many changes maybemade inthis-constru'cti'on without departing from-the scope or.

the appended claims, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only and not in a limiting sense;-

For ex ample, it may be mentioned that the mem bers 5ll and 51 may be constructed ina different or by means o i sector-like rollers which roll" down oni straight mariner.

What I claim is:

paths or in any other "know-m '1. In combination: a hot-gas pis'ton engine-ann a-piston machine operatively. associated there with, mechanical means interlinking the pistons of said hot-gas piston engine and said piston machine for maintaining constant both the strokes of all of said pistons and the phase relationship between said pistons of said hot-gas piston engine, said mechanical means consisting solely of reciprocating elements.

2. In combination: a hot-gas piston engine and a piston machine operatively associated therewith, mechanical means interlinking the pistons of said hot-gas piston engine and said piston machine for maintaining constant both the strokes of all of said pistons and the phase relationship between said pistons of said hot-gas piston engine, said mechanical means consisting solely of reciprocating elements, some of which reciprocate at right angles to the movement of said pistons and at double the frequency thereof.

3. In combination: a hot-gas piston engine and a piston machine operatively associated there- Furthermore, the shafts of the said.

with, mechanical means interlinking the pistons of said hot-gas piston engine and said piston machine for maintaining constant both the strokes of all of said pistons and the phase re-.

lationship between said pistons of saidihot-gas piston engine, said mechanical means consisting solely of reciprocating elements and including cranks. r

4. In combination: a hot-gas piston engine and. a piston .machine operatively associated therewith, mechanical means interlinking the pistons oi-isaid' hot-gas piston engine and said piston machine for maintaining constant both the strokes of all of said pistons and the phase relationship between said pistons of said hot-gas piston engine and for assuring that the pistons of said piston machine move in a sense opposite to that of said pistons of said hot-gas piston engine, said mechanical means consisting solely of reciprocating elements.

5. In combination: a hot-gas piston engine and a piston machine operatively associated therewith, mechanical means including piston rods interlinking the pistons of said hot-gas piston engine and said piston machine for maintaining constant both the strokes of all of said pistons and the-phase relationship between said pistons of said hot-gas piston engine, said mechanical means consisting solely of reciprocating elements, said reciprocating elements in turn comprising those which reciprocate longitudinally at right angles to the movement of said pistons and at double the frequency thereof, and others which connect said piston rods to said longitudinally reciprocating elements, and means including cranks constraining each of said other reciprocating elements to describe a path in the form ofan arc of a circle.

, 6. In combination: a four-cylinder hot-gas piston engine-and a four-cylinder piston machine operatively associately therewith, four piston rods each connected to a piston of said hot-gas piston engine and a piston of said piston engine, each of said piston rods intersecting a plane normal-v to said piston rods at the corners of a parallelogram, mechanical means interlinking said piston rodsofsaid hot-gas piston engine and said pistonmachine' for maintaining constant both the strokes of all of said pistons and the phase relationship between a pair of said piston rods, said mechanical means consisting solely of reciprocating elements, said reciprocating elements:

in turn comprising a pair of said elements which reciprocate longitudinally at right angles to the movement of said pistons and at double the frequency thereof, means connecting each .of said pair-of said elements to one said pairof piston ,Iods,:and coupling member means interconnecting one of each pair of piston rods tov a corresponding one of the other pair of piston rods.

.17. In combination: a four-cylinder hot-gas piston engine and a four-cylinder piston machine operatively associatedtherewith, fourpiston rods each connectedto a piston of said hot-gas piston engine and. a piston of said piston engine, each of .said piston rods intersecting a plane normal to said pistonrods at the .corners of a parallelogram, mechanical means interlinking said piston rods of said hot-gaspistonengine and said piston machine for 'maintaining constant both the strokes of all of said pistons and the phase relationship between a pair: of said piston rods, said: mechanical means consisting solely of reciprocating elements, said reciprocating elements in turn comprising a pair of said elements which reciprocate longitudinally at right angles to the movement of said pistons and at double the frequency thereof, means connecting each of said I pair of said elements to one said pair of piston rods, and coupling member means interconnecting one of each pair of piston rods to a corresponding one, of the other pair of piston rods, said mechanical means being positioned between the cylinders of said hot-gas piston engine on one side and the cylinders of said piston machine ontheother. J Y

8. In combination: a hotegas piston engine and a refrigerating apparatus operating on the reversed hot-gas engine principle associated there with, mechanical means interlinking the pistons of said hot-gas piston engine and said refrigerating apparatus for maintaining constant both the strokes'of said pistons and the phase relationship between said pistons of said hot-gas piston engine and of said refrigeratingapparatus said mechanical means consisting solely of recipro eating elements.

- ALBERT A. DROS.

REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PA'I'EN'IS Number I Du Pre Apr. 26, 1949 

